Opportunities for Methane Emissions Reductions in Natural Gas Production. Technology Transfer Workshop. April 25, 2006 Villahermosa, Mexico

Transcription

1 Opportunities for Methane Emissions Reductions in Natural Gas Production Technology Transfer Workshop PEMEX & Environmental Protection Agency, USA April 25, 2006 Villahermosa, Mexico Agenda Reduced Emissions Completions Methane Losses Methane Recovery Is Recovery Profitable? Industry Experience Discussion Questions Smart Automation Well Venting Methane Losses Methane Recovery Is Recovery Profitable? Industry Experience Discussion Questions Project Summaries for Mexico 2

2 Mexico Production Sector Methane Emissions (2000) Total Production Emissions: 27.8 Bcf Storage Tank Venting 1.7 Bcf Meters and Pipeline Leaks 2.0 Bcf Other Sources 4.0 Bcf Pneumatic Devices 11.5 Bcf Gas Engine Exhaust 2.3 Bcf Dehydrators & Pumps 3.1 Bcf Well Venting and Flaring 3.3 Bcf Sources: US Natural Gas STAR program success points to global opportunities to cut methane emissions cost-effectively, Oil and Gas Journal, July 12, 2004 Inventory of U.S. Greenhouse Gas Emissions and Sinks: Bcf = billion cubic feet 3 Methane Losses During Well Completions It is necessary to clean out the well bore and formation surrounding perforations After new well completion Completion: installation of permanent wellhead equipment for production of oil and natural gas After well workovers Workover (or cleanup): operations to restore or increase well production Operators produce the well to an open pit or tankage to collect sand, cuttings, and reservoir fluids for disposal Vent or flare the natural gas produced Venting may lead to dangerous gas buildup Flaring is preferred where there is no fire hazard or nuisance 4

3 Wellhead Gas Prices Gas prices in Mexico have increased in recent years to over $6 per thousand cubic feet ($6/Mcf) Natural Gas Price (USD per Mcf) $6.00 $5.00 $4.00 $3.00 $2.00 $1.00 $0.00 Industry Gas Price Year Source: EIA Natural Gas Price for Industry available at 5 Methane Recovery: Reduced Emissions Completions (REC) REC or Green Completions recover natural gas and condensate produced during well completions or workovers Use portable equipment to process gas and condensate suitable for sales Send recovered gas through permanent dehydrator and meter to sales line, reducing venting and flaring An estimated 25.2 Bcf or $176 million of natural gas can be recovered annually using Green Completions in U.S. 25,000 MMcf from high pressure wells 181 MMcf from low pressure wells 27 MMcf from workovers MMcf = million cubic feet 6

4 Green Completions: Equipment Truck- or trailer- mounted equipment to capture produced gas during cleanup Sand trap Three-phase separator Use portable desiccant dehydrator for workovers requiring glycol dehydrator maintenance Temporary, Mobile Surface Facilities Schematic Source: BP 7 Green Completions: Requirements Must have permanent equipment on site before workover or cleanup Piping connection to sales line Dehydrator Lease meter Stock tank Sales line gas can be used for fuel and/ or for gas lift operations and techniques in low pressure wells 8

5 Green Completions: Low Pressure Wells Can use portable compressors to start up well when reservoir pressure is low Artificial gas lift to clear fluids Boost gas to sales line Higher cost to amortize investment in portable equipment Portable Compressors, Separator and Other Equipment on a trailer Source: Herald 9 Is Recovery Profitable? U.S. companies report recovering an average of 53% of total gas lost during well completions and workovers Estimate an average of 3,000 Mcf 1 of natural gas can be recovered from each green completion Estimate 1 to 580 barrels of condensate can be recovered from each green completion 1 Values for high pressure wells 10

6 Green Completions: Benefits Reduced methane emissions during completions and workovers Sales revenue from recovered gas and condensate Improved relations with government agencies and public neighbors Improved safety Reduced disposal costs 11 Industry Experience: BP in U.S. Capital investment about $1.4 million on portable three-phase separators, sand traps, and tanks Used Green Completions on 106 wells Total natural gas recovered: about 350 MMcf per year Total condensate recovered: about 6,700 barrels per year 12

7 Industry Experience: BP in U.S. Total value of natural gas and condensate recovered: about $840,000 1,2 per year Investment recovered in just over 2 years Three Phase Separator, Source: BP 1 Value of natural gas at $1.99 per thousand cubic feet 2 Value of condensate at $22 per barrel 13 Weatherford Durango Experience Successfully completed pilot project in the Fruitland coal formations in Durango, Colorado, U.S. Well depth: 2,700 to 3,200 feet Pore pressure: estimated at 80 pounds per square inch gauge (psig) Well type: coal bed methane Hole size: 5 ½ inches Number of wells: 3 well pilots Captured 2 million cubic feet of gas which was sold by the operator 14

8 Weatherford Portable Equipment 15 Weatherford Green Completions Use pipeline gas with proprietary foaming agent as compressible fluid to initiate cleanout System includes Wet screw compressor when well pressure is less than 80 pounds per square inch gauge (psig) Booster compressor, three-phase separator and sand trap Estimate cleanup pressure of 300 to 400 psig at a well depth of 8,000 feet Suggest use in all kinds of completion and workover cleanup operations 16

9 Discussion Questions To what extent are you implementing this opportunity? Can you suggest other approaches for reducing well completion venting? How could this opportunity be improved upon or altered for use in your operation? What are the barriers (technological, economic, lack of information, regulatory, focus, manpower, etc.) that are preventing you from implementing this practice? 17 Methane Losses: Well Blowdowns Accumulation of liquid hydrocarbons or water in the well bores reduces, and can halt, production Common blow down practices to temporarily restore production can vent 80 to 1,600 Mcf per year 1 to the atmosphere per well 1 Mobil Big Piney Case Study

10 What is the Problem? Conventional plunger lift systems use gas pressure buildups to repeatedly lift columns of fluid out of well Fixed timer cycles may not match reservoir performance Cycle too frequently (high plunger velocity) Plunger not fully loaded Cycle too late (low plunger velocity) Shut-in pressure cannot lift fluid to top May have to vent to atmosphere to lift plunger Source: Weatherford 19 Conventional Plunger Lift Operations Manual, on-site adjustments tune plunger cycle time to well s parameters Not performed regularly Do not account for gathering line pressure fluctuations, declining well performance, plunger wear Requires manual venting to atmosphere when plunger lift is overloaded 20

11 Smart Automation Well Venting Automation can enhance the performance of plunger lifts by monitoring wellhead parameters such as: Tubing and casing pressure Flow rate Plunger travel time Using this information, the system is able to optimize plunger operations To minimize well venting to atmosphere Recover more gas Further reduce methane emissions 21 Methane Recovery: How Smart Automation Reduces Methane Emissions Smart automation continuously varies plunger cycles to match key reservoir performance indicators Well flow rate Measuring pressure Successful plunger cycle Measuring plunger travel time Plunger lift automation allows producer to vent well to atmosphere less frequently 22

12 Automated Controllers Low-voltage; solar recharged battery power Monitor well parameters Adjust plunger cycling Source: Weatherford Remote well management Continuous data logging Remote data transmission Receive remote instructions Monitor other equipment Source: Weatherford 23 Plunger Lift Cycle 24

13 Methane Savings Methane emissions savings is a secondary benefit Optimized plunger cycling to remove liquids increases well production by 10 to 20% 1 Additional 10% 1 production increase from avoided venting 500 Mcf per year methane emissions savings for average U.S. well 1 Reported by Weatherford 25 Other Benefits Reduced manpower cost per well Continuously optimized production conditions Remotely identify potentially unsafe operating conditions Monitor and log other well site equipment Glycol dehydrator Compressor Stock tank Vapor recovery unit 26

14 Is Recovery Profitable? Smart automation controller installed cost: about $11,000 Conventional plunger lift timer: about $5,000 Personnel savings: double productivity Production increases: 10% to 20% increased production Savings = (Mcf per year) x (10% increased production) x (gas price) + (Mcf per year) x (1% emissions savings) x (gas price) + (personnel hours per year) x (0.5) x (labor rate) $ savings per year 27 Economic Analysis Non-discounted savings for average U.S. well = (50,000 Mcf per year) x (10% increased production) x ($7 per Mcf) + (50,000 Mcf per year) x (1% emissions savings) x ($7 per Mcf) + (500 personnel hours per year) x (0.5) x ($30 per hour) - ($11,000) cost $35,000 savings in first year 3 month simple payback 28

15 U.S. Industry Experience BP reported installing plunger lifts with automated control systems on about 2,200 wells 900 Mcf reported annual savings per well $12 million costs including equipment and labor $6 million total annual savings Another company shut in mountaintop wells inaccessible during winter Installed automated controls allowed continuous production throughout the year 1 1 Morrow, Stan and Stan Lusk, Ferguson Beauregard, Inc. Plunger-Lift: Automated Control Via Telemetry Project Summary for Mexico Reduced Emissions Completions Project Description: Performing a reduced emissions completion on one high pressure well Methane Saved: Sales Value: Capital and Installation Cost 1 : 3.3 MMcf per year per well (93.5 thousand cubic meters per well) $17,300 ($5.25 per Mcf gas) ($770) per well per day (rental cost) Operating and Maintenance Cost: $10 per well per day Payback Period: 17 months Additional Carbon Market Value: $40,000 ($30 per tonne of CO 2 e) 1 One well is completed in about 30 days 30

16 Project Summary for Mexico Smart Automation Well Venting Project Description: Install one smart automated well controller on a well to increase production rate Methane Saved: 500 Mcf per year (14 thousand cubic meters per year) Sales Value: $2,600 ($5.25 per Mcf gas) Capital and Installation Cost: ($11,000) Operating and Maintenance Cost: ($1,950) per well Payback Period: 60 months Additional Carbon Market Value: $6,000 ($30 per tonne of CO 2 e) 31 Discussion Questions To what extent are you implementing this opportunity? Can you suggest other approaches for reducing well venting? How could this opportunity be improved upon or altered for use in your operation? What are the barriers (technological, economic, lack of information, regulatory, manpower, etc.) that are preventing you from implementing this practice? Reference: Unit Conversions 1 cubic foot = cubic meters Degrees Fahrenheit = ( F 32) * 5/9 degrees Celsius 1 inch = 2.54 centimeters 1 mile = 1.6 kilometers 14.7 pounds per square foot = 1 atmosphere 32